Effect of Simulated Acid Rain on the Germination, Growth, Elements, Protein and Photosynthetic Pigments Contents in Tomato (Lycopersicon esculentum)

Uncontrolled use of fossil fuels in industries and the transport sector has led to an increase in concentrations of gaseous pollutants such as sulphur dioxide (SO2), nitrogen dioxide (NO2) and their derivatives and ozone (O3). In addition to dry and wet deposition of these gases has been the major route of influx in ionic form into the ecosystem. This investigation was evaluated the effects of simulated acid rain (SAR) with different pH (6.8 as control, 6.5, 6, 5.5, 5, 4.5, 4, 3.5, 3 and 2.5) on germination, growth, elements, protein, photosynthetic pigments contents of Lycopersicon esculentum in hydroponic culture. Experiments were conducted at research laboratory of arak university in summer of 1391. Results were showed that from pH=6.8 until pH=5/5 significantly increased P and K and protein content, root and shoot dry and wet weight. SAR exposure with high acidity (pH=5/5 until pH=2.5) significantly suppressed germination, growth index, measured elements as P and K, protein and photosynthetic pigments, while significant increased sulphur contect from 150% to 550% compared to controls. Maximal amounts sulphur were measured in pH=2/5. Acid rain in low pH were decrease plant growth and make protein and incearsed sulphur content in leaf. As regards, low acidity promoted the growth of tomato plants and high acidity inhibit, Therefore, it is recommended that tomato plants cultures in soils with low acidity.